4-(4-tetrahydropyranyl)pyridines

ABSTRACT

4-(TETRAHYDROPYRANYL)PYRIDINES HAVING THE FORMULA:   R1,R2,4-(R3,R4-TETRAHYDROPYRAN-4-YL)-PYRIDINE   IN WHICH R1 AND R2 REPRESENT HYDROGEN OR LOWER ALKYL; R3 AND R4 REPRESENT HYDROGEN, LOWER ALKYL, OR PHENYL; THEY MAY BE ALIKE OR THEY MAY BE DIFFERENT. IN GENERAL THE TETRAHYDROPYRANYLPYRIDINES ARE MADE BY THE DEHYDRATION OF A PYRIDYL PENTANEDIOL.

252-146. AU 165 EX Patented May 4, 1971 Some of our tetrahydropyranylpyridines may be pre- 3,577,426 pared by the interaction of a 4-methylpyridine with di- 4-(4-TETRAHYDROPYRANYUPYRIDINES chloro ether.

Charles K. McGill and George W. Campbell, Jr., Indianapolis, Ind., assignors to Reilly Tar 8: Chemical Corporation, Indianapolis, Ind. No Drawing. Filed Jan. 31, 1969, Ser. No. 795,714 CH1 Int. Cl. c070 31/30 I U.S. Cl. 260-297 10 Claims NaNHz o1-c,rr,-o-c,n,cr 2 N301 10 ABSTRACT OF THE DISCLOSURE N 4-(tetrahydropyranyl)pyridines having the formula: K

Our tetrahydropyranylpyridines have many uses. They are useful as epoxy curing agents. They are also useful in the manufacture of acid pickling inhibitors. Poly-chloro derivatives of our tetrahydropyrauylpyridines possess R herbicidal properties. Quaternary compounds made from our tetrahydropyranylpyridines have fungicidal, bacterial, N/ as well as herbicidal properties. And they are useful inin which R and R represent hydrogen or lower alkyl; termediates in organic syntheses. R and R represent hydrogen, lower alkyl, or phenyl; The pyridylpentanediols used to make our tetrahydrothey may be alike or they may be different. In general the pyranylpyridines may be made in accordance wth the protetrahydropyranylpyridines are made by the dehydration 1 cedure described in U.S. Pat. No. 2,759,946 issued Aug. of a pyridyl pentanediol. 21. 1956.

Illustrative of the manner in which our tetrahydropyranylpyridines may be made we cite the following ex- Our present invention relates to a new composition of amplesexamples are y y of illustration y and matter. More ifi ll it relates to 4 are not to be construed as a limitation upon our invention.

'd' h th 1f 1 pyranyl)pyr1 tnes aving eogenera ormu a EXAMPLE 1 R R3 4- 4-tetrahydropyranyl) pyridine A mixture of 727 grams (4 mols) of 3-(4-pyridy1)1,5-

R 40 pentanediol and 1.5 grams of ammonium chloride is placed into a one liter three-neck flask equipped with a stirrer, thermometer, and a Dean Stark trap. The mixture wherein R, and R, represent hydrogen o lower alkyl is heated, with stirrin to a temperature of from about groups; R3 and R4 R hydrogen alkyl or 275 C. to about 290 C. It is maintained at this temperapheny]; they may be alike h be dlfierent' 4D ture for from about 10 hours to about 15 hours. During I The tetrhydmfpyranylpyndmqs which are the the heating period a reaction occurs whereby one mole- Ject mvannon t be Prepared by h thermal cule of, water is eliminated from the pentanediol, and the .flydranon of a 3'(4'Pyndy1)'1Ejentanedwh The equa' tetrahydropyran ring is formed. The water formed is coluon below, Pom-ays the -9 of lected in the Dean-Stark trap and when about four mols of pyranl)pyr1dme by the dehydration of 3-(4-pyr1dy the water are collected, the heating is discontinued, and pentanedoh the stirring is stopped.

0 The reaction mixture is now transferred to -a distilla- W tion apparatus and is distilled under reduced pressure to A yield from about 30 to about 500 grams of 4-( 4-tetra- HOCHZCHFCH CH,CH,OH hydropyranybpyndrne. The tetrahydropyranylpyridine as recovered by fractional distillation is pure enough for most purposes; it has a freezing point of about 69 C. If L a purer compound is desired, the distillation product may 6 be recrystallized from any of a number of solvents; cyclohexane is one of the preferred solvents.

Usuall we use a catalyst to assist in the formation of f y i y lPy IS a E y l i the tetra hydropyranylpyridine; among the more useful solfdi has a freeolmg P9 0f abfmt Its 19011108 catalysts we find ammonium chloride, hydrochloric acid, Point 15 abl1l22 It IS soluble in as ell as Such p-toluene sulfonyl chloride, sodium hydroxide, and the m on o ganic solvents as methanol, I P P like. zene, acetone, and the like.

3 EXAMPLE 2 4-(4-tetrahydropyranyl pyridine A solution of one mol of bis[2-chloroethyl]ether in 500 cc. of liquid ammonia is prepared. To this solution there is added within a 15 minute period, a solution composed of one mol of sodio-4-picoline in 700 cc. of liquid ammonia. After the addition has been completed, the reaction'mixture is stirred for about 30 minutes. Then there is added a slurry of one mol of sodamide in 500 cc. of liquid ammonia. The reaction mixture is stirred for about five hours, after which time 400 cc. of isopropanol is added. The ammonia is allowed to evaporate. The remaining mixture is filtered to remove the sodium chloride formed during the reaction.

The 4-(4-tetrahydropyranyl)pyridine formed is recovered from the filtrate by fractional distillation under vacuum.

EXAMPLE 3 4- (4-2methyltetrahydropyranyl pyridine The procedure of Example 1 is repeated with the exception that 160 grams of 4-(1,5-dihydroxy-3-hexyl) pyridine (prepared by the interaction of 4-propanolpyridine and propylene oxide) is used in place of the 727 grams of 3-(4-pyridyl)-1,5-pentanediol. The product of the reaction is 4-(4-2-methyltetrahydropyranyl)pyridine which boils at about 156 at 17 mm. Hg pressure.

EXAMPLE 4 3-methyl-4- 4-tetrahydropyra nyl pyridine EXAMPLE 5 4- (4-Z-phenyltetrahydropyranyl) pyridine The procedure of Example 1 is repeated with the exception that 144 grams of 4-(1,5-dihydroxy-1phenyl-3- pentyl pyridine, made by the interaction of 4-propanolpyridine and styrene oxide, are used in place of the 727 grams of 3-(4-pyridyl)-l,5-pentanediol. The 4-(4-2-phenyltetrahydropyranyl)pyridine has a boiling point of about 163 C. at 0.5 mm. Hg pressure.

EXAMPLE 6 2,6-dimethyl-4- (4-tetrahydropyranyl )pyridine The procedure of Example 1 is repeated with the exception that 176 grams of 2,6-dimethyl-4-(l,5-dihydroxy- 3-pentyl-pyridine is used in place of the 727 grams of 3-(4-pyridyl) 1,5 pentanediol. The 2,6 dimethyl-4-(4- tetrahydropyranyl)pyridine has a boiling point of about 170 C. at 20 mm. Hg pressure.

4 EXAMPLE 7 4-(4-2,6-dimethyltetrahydropyranyl) pyridine A solution of 209 grams of 4-(4-pyridyl)-2,6-heptanediol in 750 cc. of concentrated hydrochloric acid is heated under reflux conditions for about 16 hours. After the reflux period, the solution is cooled and 50% aqueous caustic soda is added to make the reaction mixture alkaline. As the reaction became alkaline two layers are formed, an aqueous layer and an organic layer. The organic layer is extracted from the mixture with methylene chloride. The 4-(4-2,6-dimethyltetrahydropyranyl)pyridine formed is recovered from the methylene chloride solution by fractional distillation under vacuum. The 4- (4-2,6-dimethyltetrahydropyranyl) pyridine distills over at 9296 C. at 0.4 mm. Hg pressure.

EXAMPLE 8 4- 4-2ethyltetrahydropyranyl pyridine The procedure of Example 1 is repeated with the exception that 186 grams of 4-(1,5-dihydroxy-3-heptyl) pyridine (prepared by the interaction of 4-propanolpyridine and butylene oxide) is used in place of the 727 grams of 3-(4-pyridyl)-1,5-pentanedio1. The 4(4-2-ethyltetrahydropyranyl)pyridine has a boiling point of about 168 at 19 mm. Hg pressure.

EXAMPLE 9 4-(4-4-methyltetrahydropyranyl) pyridine The procedure of Example 1 is repeated with the exception that 107 grams of 4-(1,5-dihydroxy-3-methyl-3- pentyl)pyridine (prepared by the interaction of 4-ethylpyridine and ethylene oxide) is used in place of the 3-(4- pyridyl) 1,5 pentanediol. The 4-(4-4-methyltetrahydropyranyl)pyridine has a boiling point of about 129 C. at 2.5 mm. Hg pressure.

EXAMPLE 10 2-methyl-4-(4-tetrahydropyranyl)Pyridine The procedure of Example 1 is repeated with the exception that 82 grams of 2-methyl-4-(1,5-dihydroxy-3- penty1)pyridine is used in place of the 727 grams of 3- (4-pyridyl)-1,5-pentanediol. The 2 methyl-4(4-tetrahyhydropyrany1)pyridine boils at about 162 C. at 21 mm. Hg pressure.

The chemical behavior of our new compounds is typical of pyridine ring containing compounds within the limitations imposed by the presence of the tetrahydropyran nucleus. They react with alkyl halides to form quaternary pyridinium compounds. Oxidation with hydrogen peroxide gives the corresponding N-oxide. Catalytic hydrogenation under pressure gives the corresponding tetrahydropyranylpiperidine.

Our tetrahydropropyranylpyridines are useful curing agents for epoxy resins. A mixture of 91 grams of an epoxy resin, Epi Rez 510 (made by Devoe & Reynolds) and 10 grams of 4-(4-tetrahydropyranyl)pyridine when wherein R and R are selected from the group consisting of hydrogen and lower alkyl, and R and R are selected form the group consisting of hydrogen, phenyl, and lower alkyl.

2. 4-(4-tetrahydropyranyl)pyridine.

3. 2-methyl-4-(4-tetrahydropyranyl) pyridine.

4, 3-methyl-4-(4-tetrahydropyranyl)pyridine.

5. 2,6-dimethyl-4-(4-tetrahydropyranyl)pyridine.

6. The process of preparing the 4-(4-tetrahydropyranyl)pyridines of claim 1 which comprises thermally dedrating a 3 (4-pyridyl)-1,5-pentanedio1 and recovering the resulting 4-(4-tetrahydropyranyl)pyridine.

7. The process of preparing 4-(4-tetrahydropyranyl) pyridine which comprises thermally dehydrating 3-(4- pyridyl)l,5-pentanediol and recovering the resulting 4- (4-tetrahydropyranyl pyridine.

8. The process of preparing 2-methyl-4-(4-tetrahydro; pyranyUpyridine which comprises thermally dehydrating 2-methyl-4(l,S-dihydroxypentyl)pyridine and recovering the resulting 2 methyl-4-(4-tetrahydropyranyl)pyridine.

9. The process of preparing 3-methyl-4-(4-tetrahydropyranyl) pyridine which comprises thermally dehydrating 3-methyl-4(1,S-dihydroxypentyl)pyridine and recovering the resulting 3 methyl-4-(4-tetrahydropyranyl)pyridine,

10. The process of preparing 2,6-dimethyl-4-(4-tetrahydropyranyl)pyridine which comprises thermally dehydrating 2,6-dimethyl-4-(1,5-dihydroxy 3 pentyl)pyridine and recovering the resulting 2,6-dimethyl-4-(4-tetrahydropyranyl)pyridine.

References Cited Sugimoto et al., Chem. Abstracts, vol. 52, page 1277, 1958.

ALAN L. ROTMAN, Primary Examiner us. 01. X.R. 260-2, 47, 999; 252-448 Notice of Adverse Decision in Interference In Interference N 0. 99 001 involving Patent No. 3,577,426. (l. K. McGill and G. W. Campbell, J12, 4-( l-TETRAHYDROPYRANYL)PYRIDINES, final judgment adverse to the patentees was rendered Nov. 18, 1976, as to claim 2.

[Oficz'al Gazette March 22, 1.977.] 

